EJScreen Indicators Overview – Drinking Water Non-Compliance

What is the drinking water non-compliance indicator?

The “drinking water non-compliance indicator” highlights populations served by community water systems that have challenges complying with Safe Drinking Water Act requirements. Points are calculated using a modified version of the EPA’s Enforcement Targeting Tool criteria, which accounts for violation severity and age. EJScreen presents drinking water non-compliance using percentile rank, ranging from 0 (lowest) to 100 (highest) with higher scores representing more compliance challenges.

Why is drinking water non-compliance important?

• The Safe Drinking Water Act (SDWA) regulates various drinking water contaminates such as lead, nitrate, E. coli, and benzene. Consuming substances above the EPA’s maximum contaminate level can be harmful.
• In the United States, an estimated 286 million people (approximately 80%) get their water from any one of the roughly 49,000 active community water systems.
• Most systems are within compliance of the EPA’s SDWA National Primary Drinking Water Regulations (NPDWR) on any given quarter. While the NPDWR aims to provide safe, clean drinking water for all consumers, some systems are in non-compliance with one or more health-based and non-health-based violations.
• A community water system free of SDWA violations suggests safe, clean drinking water. However, it is important to note that the compliance data used by this indicator does not directly measure drinking water quality as this depends on violation type and other factors unique to each water system.

How does EJScreen create the drinking water non-compliance indicator?

• The drinking water non-compliance indicator sources SDWA violation data from the EPA’s Safe Drinking Water Information System. It then translates these violations into points using a modified version of the EPA’s Enforcement Targeting Tool criteria, which accounts for violation severity and age. Scores above 0 represent the number of weighted health-based violations (including the number of years in non-compliance) and monitoring and reporting violations within a 5-year period for community water systems currently in non-compliance.
• EJScreen uses the Community Water System Service Area Boundaries dataset, which includes both state supplied and modeled boundaries, to represent the areas served by community water systems in the drinking water non-compliance indicator.
• A drinking water non-compliance score is calculated for each community water system service area. The scores are then aggregated from the service area into the census block group geography used in EJScreen. For technical details on the calculations and source data, visit the EJScreen Technical Documentation.

Moving Forward – What You Can Do

• Look up the public water system that services your area on the Safe Drinking Water Information System (SDWIS) Federal Reporting Services system. This site provides information on facilities, violations, recent site visits, and more for public water systems.
• Read your community water system’s annual Consumer Confidence Report. Community water systems are required under SDWA to provide customers with consumer confidence reports. These reports provide information on the quality of drinking water supplied to customers and can help with better understanding any risks associated with your drinking water. Some community water systems make their reports available in the EPA's online Consumer Confidence Reports Search tool. If your water systems report is not available in the EPA’s tool, reach out to your community water system directly.
• Visit the EPA’s Contact Information for Certification Programs and Certified Laboratories for Drinking Water page to find a certified laboratory in your state and learn more about available options to test your drinking water at home.
• Stay informed on the latest relevant information and resources on the EPA’s Drinking Water program.
• Build community-based water resiliency. The EPA Communities and Utilities Partnering for Water Resilience page provides many strategies and resources for building resiliency.
• Explore detailed information about the conditions of your local waters and drinking water providers on the EPA How’s My Waterway Tool.
• Learn more about drinking water sources with the EPA’s Drinking Water Mapping Application to Protect Source Waters (DWMAPS).